Minimally invasive surgical procedures are widely used today instead of major surgery procedures, or as preliminary procedures allowing inspection of diseased/abnormal tissues of the subject (e.g. patient's body). In such procedures, relatively small surgical tools are typically directed through the body portion towards the region of interest therein (for example utilizing natural cavities (lumens) in the body, or minimal surgical openings, e.g. single-aperture or multi-aperture laparoscopy).
It is very often the case that such minimally invasive procedures are incapable of examining the region of interest (e.g. the type of the tissue thereon) in real time just prior to removing the tissue portion. Various techniques have been developed to facilitate tissue inspection while removing the tissue portions, and are described for example in the following publications:
U.S. Pat. No. 4,955,383 discloses a method and apparatus for determining the presence or absence of a disease condition at a test site on a human or animal subject by detecting during a test period the respective electrical potentials of the electromagnetic field present in the subject between each of a plurality of measurement locations in the area of the test site and at least one reference location. A representative potential is separately obtained for each measurement location during the test period, and these representative potentials are compared at the end of the test period to obtain relationships therebetween which are indicative of either the presence or absence of a disease condition. US patent publication No. 2002/128570 discloses technique for quantifying perfusion and removing a biopsy sample at a site in a living body wherein an instrument having a perfusion sensor is introduced into the body at a site to be investigated to there interrogate the tissue. The biopsy specimen is collected when the perfusion sensor produces a signal indicative of perfused, viable tissue.
U.S. Pat. No. 6,546,787 discloses diagnostic imaging methods, methods of detecting the margin of tissue structures and bioresponsive needle systems are disclosed. The methods rely on the use of strain signals provided by a strain gage mounted on the wall of one or more needles as the needle or needles are moved through tissue. The systems employ a strain gage mounted on the wall of the needle and a strain monitor providing feedback to a user.